Crystal forms of saxagliptin

ABSTRACT

The present invention relates to novel polymorphic forms of Saxagliptin Hydrochloride. The present invention also relates to methods of making polymorphic forms of Saxagliptin Hydrochloride.

The present invention relates to novel polymorphic forms of SaxagliptinHydrochloride, their preparation and compositions containing them.

Saxagliptin(1S,3S,5S)-2-[(2S)-2-amino-2-(3-hydroxy-1-adamantyl)acetyl]-2-azabicyclo[3.1.0]hexane-3-carbonitrileor its hydrochloride salt is an orally active reversible dipeptidylpeptidase-4 (DD4) inhibitor, which is a therapeutic agent for treatmentof type-2 diabetes mellitus, obesity or related diseases, and isdisclosed for example in U.S. Pat. No. 6,395,767 B2, example 60.

Certain crystal forms of Saxagliptin and certain acid addition saltsincluding Saxagliptin Hydrochloride are disclosed in WO 2008131149 A2.The occurrence of different crystalline forms of a single compound isknown as polymorphism and is a property of some compounds and complexesand pseudopolymorphs. Polymorphic forms each have distinct physicalproperties, such as a distinct solubility profile, different meltingpoint and/or different x-ray diffraction peaks.

Since the solubility of each polymorph may vary, identifying theexistence of pharmaceutical polymorphs is important for providingpharmaceutical compositions with predictable solubility profiles. It isdesirable to investigate all solid state forms of a drug, including allpolymorphic forms, pseudopolymorphs and hydrates, and to determine thestability, dissolution and flow properties of each polymorphic form. Fora general review of polymorphs and the relevance of solid stateproperties for pharmaceutical products see e.g. Rolf Hilfiker,Polymorphism in the Pharmaceutical industry, Wiley-VCH 2006.

The discovery of new polymorphic forms of a pharmaceutically usefulcompound provides a new opportunity to improve the performancecharacteristics of a pharmaceutical product. It enlarges the repertoireof materials that a formulation scientist has available for designing,for example, a pharmaceutical dosage form of a drug with a targetedrelease profile or other desired characteristic.

The known polymorphic forms of Saxagliptin hydrochloride are allhydrated forms having a relatively high water content. High-watercontent forms have certain drawbacks, as a compound prone to hydrolysislike Saxagliptin can show decreased chemical stability when present insuch forms. Moreover, from a galenical perspective, bulk quantities ofactive pharmaceutical ingredients having a high water content tend toclog or stick together, thus sometimes having poor processing behaviorin the formulation processes for the production of pharmaceuticalcompositions.

There is thus a need for solid forms of Saxagliptin hydrochloride whichavoid one or more problems of the known crystal forms.

In accordance with the present invention new anhydrous forms ofSaxagliptin Hydrochloride preferably of the formula

are provided having a water content of not more than 1.5% w/w preferablyin substantially pure form asa) an anhydrous form designated as Form I-Sb) an anhydrous form designated as form HT-Sc) an anhydrous form designated as form HT-IV-Sd) an anhydrous form designated as form IV-S.

The water content is determined according to the Karl Fischer method.

An anhydrous form of Saxagliptin hydrochloride in the context of thepresent invention is defined as a form of Saxagliptin hydrochloridewhich, after storage at 30% relative humidity at 25° C. for 24 hoursshows a water content of not more than 1.5% w/w according to the KarlFischer method.

DETAILED DESCRIPTION

The Saxagliptin hydrochloride used as educt is one of the known formscontaining water, e.g. forms H2-1, H1.25-2 or H.75-3 as identified in WO2008/131149 A2 on page 2.

Form I-S

In a first aspect the present invention provides a crystalline form ofSaxagliptin hydrochloride, designated as form I-S, which can becharacterized by x-ray powder diffraction reflections at about 6.7,14.6, 15.2, 16.6 and 17, 9±0.2 degrees two-theta, in particularcomprising further peaks at about 13.5, 24.5 and 28.1. Form I S ofSaxagliptin can be further characterized by a PXRD pattern substantiallyin accordance with FIG. 1.

Alternatively crystalline form I-S of Saxagliptin hydrochloride can bedescribed by an infrared spectrum comprising peaks at wavenumbers of2907, 2853, 1637, 1589, 1462, 1391, 1318, 1045, 1014 and 775+/−2 cm-1.Form I S of Saxagliptin hydrochloride can be further characterized by anFTIR spectrum substantially in accordance with FIG. 2.

Anhydrous crystalline Saxagliptin hydrochloride in the form of form I-Scan be prepared by crystallization of Saxagliptin hydrochloride from analcohol, preferably ethanol in the presence of seeds of from I-S, forexample as described in example 2. Seeds of from I-S were surprisinglyobtained by dissolving Saxagliptin free base hemihydrate in an organicsolvent, precipitation with an alkyl halide dihydrate, removingprecipitated Saxagliptin monohydrochloride dehydrate and crystallizingfrom the mother liquor after cooling, see example 1. CrystallineSaxagliptin hydrochloride form I-S is a particularly preferred crystalform due to its high chemical stability combined with its highdissolution rate.

Form HT-S

In a second aspect the present invention provides a crystalline form ofSaxagliptin hydrochloride, designated as form HT-S, which can becharacterized by x-ray powder diffraction reflections at about 6.6,11.5, 13.3, 16.7 and 17.6±0.2 degrees two-theta, in particularcomprising further peaks at about 11.5 and 15.3. Form HT-S ofSaxagliptin can be further characterized by a PXRD pattern substantiallyin accordance with FIG. 4.

Alternatively crystalline form HT-S of Saxagliptin hydrochloride can bedescribed by an infrared spectrum comprising peaks at wavenumbers of2906, 2854, 1649, 1574, 1513, 1459, 1338, 1124, 1032 and 851+/−2 cm-1.Form HT-S of Saxagliptin hydrochloride can be further characterized byan FTIR spectrum substantially in accordance with FIG. 5.

The crystalline Saxagliptin hydrochloride in the form of HT-S can beprepared by heating known forms Saxagliptin hydrochloride to about 160°C. to 180° C. and isolating form HT-S. In particular, form HT-S may beprepared as described in example 3.

Form HT-IV-S

In a third aspect the present invention provides a crystalline form ofSaxagliptin hydrochloride, designated as form HT-IV-S, which can becharacterized by x-ray powder diffraction reflections at about 2.6, 4.5,6.8, 14.6 and 18.1±0.2 degrees two-theta. Form HT-IV-S of Saxagliptincan be further characterized by a PXRD pattern substantially inaccordance with FIG. 7.

Alternatively crystalline form HT-IV-S of Saxagliptin hydrochloride canbe described by an infrared spectrum comprising peaks at wavenumbers of3495, 2921, 1637, 1616, 1464, 1242, 1103, 1013, 940 and 774+/−2 cm-1.Form HT-IV-S of Saxagliptin hydrochloride can be further characterizedby an FTIR spectrum substantially in accordance with FIG. 8.

The crystalline Saxagliptin hydrochloride in the form HT-IV-S can beprepared by removing bound solvent from Saxagliptin-IV-S. In particularthe form HT-IV-S can be obtained by drying the form IV-S described belowin vacuo, e.g. at ambient temperature to about 100° C., e.g. at about80° C.±10° C. for several hours, e.g. for 3 to 24 hours. In particularform HT-IV-S may be prepared as described in example 4. In one preferredembodiment Saxagliptin hydrochloride form HT-IV-S is prepared in aprocess comprising the steps of

-   a) dissolving Saxagliptin monohydrochloride in n-butanole,-   b) removing n-butanole under reduced pressure to obtain a residue,-   c) adding 2-methyl-2-butanol to obtain a slurry,-   d) allowing a solvated crystalline form of Saxagliptin hydrochloride    to form in the slurry,-   e) removing the solvated crystalline form from the slurry, and-   f) drying the solvated crystalline form obtained from step e) to    obtain the anhydrous crystalline Saxagliptin hydrochloride form    HT-IVs. Drying in step f) is preferably carried out at 80°    C.+/−10° C. for 3-24 hours.

Form IV-S

Saxagliptin form IV-S can be characterized by x-ray powder diffractionreflections at about 2.4, 4.1, 4.7, 6.3 and 15, 6±0.2 degrees two-theta.Form IV-S of Saxagliptin can be further characterized by a PXRD patternsubstantially in accordance with FIG. 1.

The crystalline Saxagliptin hydrochloride in the form of form IV-S canbe, and preferably is prepared by crystallisation of Saxagliptinhydrochloride from tert. Amylalkohol (2-methyl-2-butanol) as describedin example 5. A solution of Saxagliptin Hydrochloride in n-butanole isevaporated to dryness to produce an amorphous or weakly crystallineresidue. Upon suspending the residue in tert.amylalkohol the novelcrystalline form IV-S of Saxaglipin Hydrochloride is formed, which is atert.amylcohol solvate of Saxagliptin hydrochloride.

Saxagliptin hydrochloride form IV-S is a valuable intermediate in thepreparation of Saxagliptin hydrochloride form HT-IV-S.

Most preferably the solution of Saxagliptin hydrochloride is preparedusing known form Dihydrate H2.1. The crystals are then isolated and keptat a relative humidity of less than to about 40%.

Pharmaceutical Formulations and Compositions

Any one of the crystal forms of Saxagliptin Hydrochloride of theinvention as described above may be employed in various pharmaceuticalformulations for use in treating diabetes and related diseases inaccordance with the present invention. The present invention thereforealso relates to a pharmaceutical composition which includes any one ofthe crystalline forms of saxagliptin hydrochloride as described aboveand a pharmaceutically acceptable carrier.

The novel crystal forms of Saxagliptin Hydrochloride may be used aloneor in combination with one or more types of antidiabetic agents(employed to treat diabetes and related diseases) and/or one or moreother types of therapeutic agents which may be administered orally inthe same dosage form, in a separate dosage form or by injection.

The other types of antidiabetic agent which may optionally be employedin combination with the novel crystal forms of the compound of formula Iare further antidiabetic agents or antihyperglycemic, hypolipidemic orlipid-modulating agents including insulin secretagogues or otherantidiabetic agents preferably having a mechanism different from DP4inhibition and may include biguanidines, sulfonyl ureas, glucosidaseinhibitors, PPAR γ agonists, such as thiazolidinediones, SGLT2inhibitors, PAR α/γ dual antagonists, aP″ inhibitors, glycogenphosphorylase inhibitors, and/or meglitinides, as well as insulin and/orglucagons-like peptide-1 (GLP-1) or mimetics thereof.

The present invention also relates to a pharmaceutical compositioncontaining the novel crystalline forms form I-S, form HT-S, form HT-IVor form IV-S of the compound of formula I, with or without anotherantidiabetic agent and/or other therapeutic agent, in association with apharmaceutical vehicle or diluent. The pharmaceutical composition can beformulated employing conventional solid or liquid vehicles or diluentsand pharmaceutical additives of a type appropriate to the mode ofdesired administration. For example, for the administration by an oralroute the pharmaceutical composition of the invention may be in the formof tablets, capsules, granules or powders. The dose for adults ispreferably between 5 mg to 1000 mg per day, preferably between 5 and 100mg per day, which can be administered in a single dose or in theindividual doses from 1-4 times a day.

The pharmaceutical compositions of the invention comprising thecrystalline form of Saxagliptin hydrochloride according to the presentinvention may further comprise one or more pharmaceutically acceptableexcipients which are preferably selected from the group consisting offillers, sweeteners, buffering agents, glidants, flowing agents,flavoring agents, lubricants, preservatives, surfactants, wettingagents, binders, disintegrants and thickeners. Other excipients known inthe field of pharmaceutical compositions may also be used. Furthermore,the pharmaceutical compositions may comprise a combination of 2 or moreexcipients also within one of the members of the above mentioned group.Preferably, the fillers are also sweeteners.

A typical tablet contains a one or more excipients such as bulkingagents, optionally a binder and optionally a disintegrant. Examples ofbulking agents include cellulose derivatives, such as microcrystallinecellulose, lactose, sucrose, starch, pregelatinized starch, dextrose,mannitol, fructose, xylitol, sorbitol, corn starch, inorganic salts suchas calcium salts, e.g. calcium carbonate, calcium phosphate, dicalciumphosphate, dextrin or dextrates, maltodextrin compressable sugars and/orother known bulking agents or fillers.

Examples of binders suitable for use include hydroxypropylcellulose,PVP, starch, hydroxypropylcellulose, cellulose acetate as well as a waxbinder such as carnauba wax, polyethylenes or other conventional bindingagents or mixtures thereof.

Examples of disintegrants include croscarmellose sodium, crospovidone,starch, low substituted hydroxypropyl cellulose as well as otherconventional desintegrants.

The lubricant optionally present include for example magnesium stearate,zinc stearate, calcium stearate, talc, carnauba wax, stearic acid,palmitinic acid, sodium laurylsulfate or hydrogenated vegetable oils andfats or other known lubricats or mixtures thereof.

Tablets may be coated including a tablet core and a inner seal coatinglayer coated on the tablet core, a second coating layer containing thecrystals of the present invention coated on the inner seal coating onthe tablet core and optionally an outer protective coating layer coatedon the second coating layer of the tablet as e.g. disclosed in US2005/0266080.

The present invention therefore also provides such coated tablets asdescribed in sections [0014] to section [0073] of US 2005/0266080 A1,where it is to be understood that whenever US 2005/0266080 A1 is usingthe term “medicament”, the crystalline saxagliptin hydrochloride of thepresent invention is to be used instead of the “medicament” of US2005/0266080 A1. It goes without saying that especially when form I-S,form IV-S or form HT-IV-s is used, all steps are typically carried outunder such conditions which avoid polymorphic transformation, such asconditions of relatively low relative humidity.

Typical capsules for oral administration containing the novelcrystalline forms of the invention contain e.g, lactose, crosscarmelose,magnesium stearate or e.g. sodium stearyl fumararte.

Purity

The present inventors have found ways to stabilize especially form I-S,form HT-IV-S and form IV-S during the formulation and storage process.

The present invention therefore also relates to a pharmaceuticalcomposition comprising the crystalline form of Saxagliptin hydrochloridedesignated as form I-S, wherein more than 95% of the crystalline form ofSaxagliptin hydrochloride, designated as form I-S, present in saidcomposition is stably present as form I-S, in particular, the presentinvention relates to such pharmaceutical compositions wherein form I-Sis the only detectable crystalline from of Saxagliptin hydrochloride.

The present invention therefore also relates to a pharmaceuticalcomposition comprising the crystalline form of Saxagliptin hydrochloridedesignated as form HT-IV-S, wherein more than 95% of the crystallineform of Saxagliptin hydrochloride, designated as form HT-IV-S, presentin said composition is stably present as form HT-IV-S, in particular,the present invention relates to such pharmaceutical compositionswherein form HT-IV-S is the only detectable crystalline from ofSaxagliptin hydrochloride.

The present invention therefore also relates to a pharmaceuticalcomposition comprising the crystalline form of Saxagliptin hydrochloridedesignated as form IV-S, wherein more than 95% of the crystalline formof Saxagliptin hydrochloride, designated as form IV-S present in saidcomposition is stably present as form IV-S, in particular, the presentinvention relates to such pharmaceutical compositions wherein form IV-Sis the only detectable crystalline from of Saxagliptin hydrochloride.

“Stably present” as defined herein means that even after storage of thepharmaceutical composition for 180 days, and preferably even afterstorage for two years, the crystalline form of Saxagliptin hydrochlorideinitially comprised in the pharmaceutical composition is still presentas crystalline form of Saxagliptin hydrochloride after storage for theindicated period. Such compositions can be produced by avoiding humidconditions, such as high relative humidity of the air, during theformulation steps. Furthermore, the above-identified humid conditionsare to be avoided during storage in order to preserve the pharmaceuticalcomposition of the invention.

In a preferred embodiment the pharmaceutical composition of theinvention comprises the crystalline form of Saxagliptin hydrochloridedesignated as form I-S as the only detectable form of Saxagliptinhydrochloride. Analysis of the polymorphic state of Saxagliptinhydrochloride in a pharmaceutical composition can be performed by anysuitable method known in the art, for example by XRPD.

Equilibrium Humidity

It is preferred that the pharmaceutical composition of the inventioncomprising the crystalline form of Saxagliptin hydrochloride designatedas form I-S or form HT-IV-S exhibits an equilibrium relative humidity ofbelow 50%, preferably of from 3% to 50%, more preferably of from 10% to45%, preferably from 15% to 45%, in particular more preferably of from15% to 40% or from 25% to 35%, for at least 180 days, preferably for atleast two years.

It is preferred that the pharmaceutical composition of the inventioncomprising the crystalline form of Saxagliptin hydrochloride designatedas form IV-S exhibits an equilibrium relative humidity of below 40%,preferably of from 3% to 40%, more preferably of from 10% to 40%,preferably from 15% to 40%, in particular more preferably of from 15% to40% or from 25% to 35%, for at least 180 days, preferably for at leasttwo years.

The equilibrium relative humidity of the pharmaceutical compositionscomprising the crystalline form of Saxagliptin hydrochloride is measuredby determining the relative humidity in % in the air above a testsample, e.g. a pharmaceutical composition of the invention comprisingthe crystalline form of Saxagliptin hydrochloride designated as form I-Sor form HT-IV-S, after establishment of a humidity equilibrium in aclosed system at a constant temperature according to the followingmethod: the equipment used is the commercially available measuringchamber Rotronic AW-VC comprising a hygrometer of the type BT-RS1. Thetest sample, e.g. a pharmaceutical composition of the invention isfilled into a sampling dish which is placed into the measuring chamberwhich has been thermostated to a temperature of 25+/−1° C., said chamberis subsequently closed and sealed. After establishment of an equilibriumof the relative humidity which state is typically shown by thedisappearance of a trend indication, the value of the relative humidityin % is read from the hygrometer. Relative humidity is defined as theequilibrium relative humidity of the pharmaceutical compositions asmeasured as herein described. Filling of the chamber is to be performedin such a way as to provide complete filling of said chamber accordingto the instructions of the manufacturers. In case the test sample is apowder or granules for oral suspension, or a liquid suspension, saidsample is directly placed into the above mentioned sampling dish. Incase the test sample is a capsule, the appropriate number of capsules isopened and their contents is filled into the sampling dish. In case thetest sample is a tablet, the appropriate number of tablets is crushed byusing a mortar, and filled into the sampling dish. In cases where theequilibrium humidity is expected to be below 20%, the above describedpreparation of the test samples before measurement and the measurementitself as herein described is to be performed in a glove box beingequipped with a hygrometer wherein a relative humidity of about 5% is tobe established by e.g. flushing with dried air or nitrogen. The abovedescribed method for measurement of the equilibrium relative humidity ofthe pharmaceutical compositions of the invention is herein also calledERH method.

Storage Conditions

The pharmaceutical composition of the present invention comprising thecrystalline form of Saxagliptin hydrochloride designated as form I-S,IV-S or form HT-IV-S is preferably stored in a relatively dryenvironment, and preferably it is to be assured that the storageenvironment remains relatively dry during the lifetime of thepharmaceutical composition.

In one preferred embodiment the compounds and compositions especiallyform I-S and HT-IV-S according to the present invention are stored in acontainer capable to keep the equilibrium relative humidity of thecomposition at below 50%, preferably at from 10% to 45%, more preferablyat from 15% to 40%, for at least 180 days, more preferably for at leasttwo years. This can be achieved, for example, by use of a tightly sealedcontainer, or by equipping the container with a means to keep thecomposition relatively dry.

In another preferred embodiment, the invention therefore also relates toa container comprising a pharmaceutical composition of the inventioncomprising the crystalline form of Saxagliptin hydrochloride designatedas form IV-S, which container is capable to keep the equilibriumrelative humidity of the composition at below 40%, preferably at from10% to 40%, more preferably at from 15% to 40%, for at least 180 days,more preferably for at least two years. This can be achieved, forexample, by use of a tightly sealed container, or by equipping thecontainer with a means to keep the composition relatively dry.

Such a drying means may be, for example, desiccant bags, e.g. ascommercially available under the trade name MINIPAX and containing 2 gof molecular sieve 4 Angstrom; or desiccant canisters, e.g. as availableunder the trade name SORBIT and containing 1 g Silicagel; desiccantcapsules, e.g. as available under the trade name DRICAP, and containing0.9 g Silicagel, or desiccant stoppers containing 2 g Silicagel.

Storage Container

The products or intermediate products obtained in the various steps ofherein described processes are preferably stored at an environmentalrelative humidity of below 50%, preferably below 40%. Said products maythus be stored in aluminium barrels or drums, in so-called Nirosta®drums, such as commercially available as Müller® drums. Said drums maybe made gas-tight, e.g. air-tight by applying a sealing means, such assealing rings to the lid thereof. Said products may also be stored incontainers made of aluminium or Nirosta®-material as mentioned abovewhereof the closures or lids are provided with a sealing means, such asa sealing ring.

The pharmaceutical compositions of the invention comprising thecrystalline form of Saxagliptin hydrochloride especially designated asform I-S or form HT-IV-S are preferably packaged or filled intocontainers as herein described at an environmental relative humidity ofbelow 50%, preferably at from 10% to 45%. Subsequently, said containersare tightly closed as herein described. Preferably, said containers areused for stable storage of the pharmaceutical compositions of theinvention, for example at room temperature, such as at a temperature ofabout 20° C. to 30° C., e.g. at about 25° C., for a prolonged period,e.g. for at least 6 months, preferably at least about 24 months, e.g.for up to at least 24 months, e.g. for up to at least about 30 months,such as for up to about 60 months.

The pharmaceutical compositions of the invention comprising thecrystalline form of Saxagliptin hydrochloride designated as form IV-Sare preferably packaged or filled into containers as herein described atan environmental relative humidity of below 40%, preferably at from 10%to 40%. Subsequently, said containers are tightly closed as hereindescribed. Preferably, said containers are used for stable storage ofthe pharmaceutical compositions of the invention, for example at roomtemperature, such as at a temperature of about 20° C. to 30° C., e.g. atabout 25° C., for a prolonged period, e.g. for at least 6 months,preferably at least about 24 months, e.g. for up to at least 24 months,e.g. for up to at least about 30 months, such as for up to about 60months.

A preferred container is a bottle, e.g. a glass or plastic bottle, e.g.a polyethylene bottles, such as known as securitainer, having e.g. ascrew closure, or is a blister, e.g. an aluminium blister or strip, e.g.a blister consisting of 2 aluminum foils or strips, or a blistercomprising an Aclar® foil and an aluminum cover foil, or may be anyother suitable container. More preferably said container is a gas-tightcontainer, such as an air-tight container.

Preferred containers are glass or plastic bottles sealed with analuminum membrane, alu-alu-blisters or strips, or blisters comprising anAclar® foil and an aluminum cover foil. The container according to theinvention is obtained by filling the pharmaceutical compositions of theinvention into said container under the conditions as herein described.

Preferably, the container in combination with the drying means iscapable of maintaining the equilibrium relative humidity of thepharmaceutical composition of the invention comprising the crystallineform of Saxagliptin hydrochloride designated as form I-S or form HT-IV-Stherein at below 50%, preferably at from 10% to 45%, for at least 6months, preferably for at least two years. In a preferred embodiment thecontainer further encloses a gaseous atmosphere with a relative humidityof below 50%, preferably of from 10% to 45%. Equipping the containerwith a dry gaseous atmosphere, for example dry air or dry nitrogen gas,can be performed as known in the art. With regard to form IV-S thecontainer in combination with the drying means is capable of maintainingthe equilibrium relative humidity of the pharmaceutical composition atbelow 40%, preferably at from 10% to 40%, for at least 6 months,preferably for at least two years. In a preferred embodiment thecontainer further encloses a gaseous atmosphere with a relative humidityof below 40%, preferably of from 10% to 40%.

Preferred combinations of container and drying means arealuminum-foil-sealed polyethylene-bottles (PE-bottles) containingdesiccant capsules and/or canisters or glass bottles with desiccantstoppers.

Preparation of Compositions

Special care as to the relative environmental humidity and as to theequilibrium relative humidity of the composition has to be taken duringthe production of pharmaceutical compositions of the inventioncomprising form I-S, IV-S or form HT-IV-S. Therefore, the presentinvention also relates to a process for preparing a pharmaceuticalcomposition of the invention comprising the crystalline form ofSaxagliptin hydrochloride designated as form I-S, IV-S or form HT-IV-Scomprising the steps of

-   a) mixing the crystalline form of Saxagliptin hydrochloride    designated as form I-S or form HT-IV-S with one or more    pharmaceutically acceptable excipients at a relative humidity of    below 50%, preferably at from 10% to 45% and as regards form IV-S at    a relative humidity of below 40%, preferably at from 10 to 40%;-   b) optionally granulating the mixture obtained in step a) at a    relative humidity of below 50%, preferably at from 10% to 45% as    regards form I-S and HT-IV-S and at a relative humidity of below    50%, preferably at from 10% to 40% as regards form IV-S; and-   c) further processing the mixture obtained in step a) or the    granulate obtained in step b) at a relative humidity of below 50%,    preferably at from 10% to 45% as regards form I-S and HT-IV-S and at    a relative humidity of below 40%, preferably at from 10% to 40% as    regards form IV-S, to obtain a pharmaceutical composition of the    invention comprising the crystalline form of Saxagliptin    hydrochloride designated as form I-S or as form HT-IV-S or as form    IV-S. It is preferred that the obtained pharmaceutical composition    of the invention exhibits an equilibrium relative humidity of below    50%, preferably of from 10% to 45%, more preferably of from 15% to    30% or of from 20% to 45% as regards form I-S and HT-IV-S and an    equilibrium relative humidity of below 40%, preferably of from 10 to    40%, more preferably of from 15 to 30% as regards form IV-S.

The mixture obtained from step a) or the granulate obtained from step b)as described above is preferably processed into an oral dosage form,like a capsule or a tablet, or granules for oral suspension, or a powderfor oral suspension.

In a preferred embodiment, the obtained pharmaceutical compositioncomprising the crystalline form of Saxagliptin hydrochloride designatedas form I-S or form HT-IV-S having an equilibrium relative humidity ofbelow about 50%, preferably of from 10% to 45%, is filled into acontainer capable of maintaining the equilibrium relative humidity ofthe pharmaceutical composition at below 50%, preferably at from 10% to45%, for at least 6 months, for examples the containers mentioned above,which may optionally further comprise a drying means sufficient tomaintain the equilibrium relative humidity of the pharmaceuticalcomposition at below 50%, preferably at from 10% to 45%.

The proper storage conditions for the pharmaceutical compositions of theinvention comprising the crystalline form of Saxagliptin hydrochloridedesignated as form I-S or form HT-IV-S are important for maintaining thecompositions in the desired form. Thus, preferably a container is usedcapable of maintaining a gaseous atmosphere at a relative humidity ofbelow 50%, preferably at from 10% to 45%, for at least 6 months forstorage of a pharmaceutical composition of the invention. Preferably, agaseous atmosphere having a relative humidity of below 50%, preferablyat from 10% to 45%, is used to stabilize the crystalline form ofSaxagliptin hydrochloride designated as form I-S or form HT-IV-S and arelative humidity of below 40%, preferably at from 10% to 40% as regardsform IV-S.

After the pharmaceutical compositions of the invention have been filledinto the herein mentioned containers, said containers are preferablytightly closed, e.g. tightly or hermetically sealed, e.g. in a way toprevent any gaseous atmosphere from diffusing through the walls and/orclosure of said containers. Methods of tightly sealing and/or closingsaid containers are known, such as sealing of glass or plastic bottlesby applying an aluminium membrane to the bottle opening of said bottleby induction sealing and by applying a closure, e.g. a screw closure, orsuch as sealing of alu-alu blisters or strips, of blisters comprising anAclar® foil and an aluminium cover foil by heat sealing according, e.g.analogously to known methods.

The temperature applied during the herein described processes ispreferably room temperature, e.g. is a temperature of about 20° C. toabout 30° C., such as about 25° C.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: PXRD pattern of Saxagliptin Hydrochloride form I-S

FIG. 2: FTIR spectrum of Saxagliptin Hydrochloride form I-S

FIG. 3: DSC of Saxagliptin Hydrochloride form I-S

FIG. 4: PXRD pattern of Saxagliptin Hydrochloride form HT-S

FIG. 5: FTIR spectrum of Saxagliptin Hydrochloride form HT-S

FIG. 6: DSC of Saxagliptin Hydrochloride form HT-S

FIG. 7: PXRD pattern of Saxagliptin Hydrochloride form HT-IV-S

FIG. 8: FTIR spectrum of Saxagliptin Hydrochloride form HT-IV-S

FIG. 9: DSC of Saxagliptin Hydrochloride form HT-IV-S

FIG. 10: PXRD pattern of Saxagliptin Hydrochloride form IV-S

FIG. 11: TGA of Saxagliptin Hydrochloride form IV-S

EXAMPLES

X-ray powder diffraction patterns (XRPD) were obtained with aPANalytical X′Pert PRO diffractometer equipped with a theta/thetacoupled goniometer in transmission geometry, Cu-Kα_(1,2) radiation(wavelength 0.15419 nm) with a focusing mirror and a solid state PIXceldetector. The patterns were recorded at a tube voltage of 40 kV, tubecurrent of 40 mA, applying a stepsize of 0.006° 2θ with 80 s per step inthe angular range of 2° to 40° 2θ at ambient conditions. A typicalprecision of the 2-theta values is in the range of about ±0.2° 2-theta.Thus a diffraction peak that appears at 5.0° 2-theta can appear between4.8 and 5.2° 2-theta on most X-ray diffractometers under standardconditions.

Infrared spectra (IR) were collected on a MKII Golden Gate™ SingleReflection Diamond ATR (attenuated total reflection) cell with a BrukerTensor 27 FTIR spectrometer with 4 cm⁻¹ resolution. To collect aspectrum a spatula tip of a sample was applied to the surface of thediamond in powder form. Then the sample was pressed onto the diamondwith a sapphire anvil and the spectrum was recorded. A spectrum of theclean diamond was used as background spectrum. A typical precision ofthe wavenumber values is in the range of about ±2 cm⁻¹. Thus, aninfrared peak that appears at 1716 cm⁻¹ can appear between 1714 and 1718cm⁻¹ on most infrared spectrometers under standard conditions.

Differential scanning calorimetry (DSC) was performed with a DSC 7(Perkin-Elmer, Norwalk, Conn., USA) using the Pyris software. A sampleof about 4 mg was weighed into a 25 μl Al-pan. Dry nitrogen was used asthe purge gas (purge: 20 ml min⁻¹). When used herein, the term“T_(onset)” determined by Differential Scanning calorimetry means thetemperature corresponding to the intersection of the pretransitionbaseline with the extrapolated leading edge of the transition.

Thermogravimetric analysis was performed with the thermogravimetricsystem TGA-7 using the Pyris Software for Windows NT (Perkin-Elmer,Norwalk, Conn., USA), 50 μl platinum pans, nitrogen purge gas (samplepurge: 20 ml min⁻¹, balance purge: 40 ml min⁻¹).

The moisture sorption isotherm was recorded with a SPS-11 moisturesorption analyzer (MD Mess-technik, Ulm, D). The measurement cycle wasstarted at 0% relative humidity (RH), increased in 10% steps up to 90%RH and in a 5% step up to 95% RH. The equilibrium condition for eachstep was set to a constant mass ±0.003% over 49 min. The temperature was25±0.1° C.

HPLC assay was performed by applying the following conditions:

Column: YMC-Ultra HT Pro C 18 3.0×50.0 mm, 2 μm

Eluent: A 10 mM Sulfamic acidEluent: B 250 ml 10 mM SAS+750 ml acetonitrilFlow rate: 0.64 ml/min

Temperature: 15° C. Detection: UV at 210 nm Gradient:

t [min] 0 10 12 12.1 15 % B 0 70 70 0 0Stop time: 15 minSample concentration: about 0.5 mg/ml

Solvent: Eluent A Injection Vol: 5 μl Example 1 Preparation of AnhydrousForm I-S of Saxagliptin Monohydrochloride

4.58 g Saxagliptin free base hemihydrate were dissolved in 230 mlacetone. To this solution 2.2 ml Trimethylchlorosilane were added understirring. After one hour the mixture containing a gelatinous precipitatewas evaporated. To the solid residue 80 ml ethanol was added and theslurry was stirred in an open flask for about one hour. The product wasfiltered off, washed with tert.-Butyl methyl ether and then dried in avacuum oven to give 1.65 g Saxagliptin Monohydrochloride Dihydrate.Polymorphism of Saxagliptin Monohydrochloride Dihydrate was determinedby X-ray diffraction, FT-IR and DSC.

The mother liquor was put into a refrigerator at −5° C. for 48 hours.Surprisingly, additional crystals had formed from the mother liquor. Theso obtained crystalline precipitate was filtered off, washed withtert.-Butyl methyl ether and then dried in a vacuum oven. The crystalswere analyzed and found to be 1.22 g Saxagliptin Monohydrochloride. Theobtained product from the mother liquor was found to be a new anhydrouspolymorphic form of Saxagliptin Monohydrochloride, denominated as formI-S.

purity by HPLC: 99.7 area % (max individual impurity 0.09%, totalimpurities 0.33%)

The powder X-ray diffraction pattern of Saxagliptin Monohydrochlorideform I-S is shown in FIG. 1. Characteristic XRPD angles, d-spacings andrelative intensities are shown in Table 1.

TABLE 1 Angles 2-theta, d-values and relative intensities of form I-SAngle d value rel. Int. [2-Theta °] [Angstrom] [%] 6.72 13.145 100 10.308.591 4 11.68 7.577 3 13.52 6.548 12 14.63 6.054 46 15.15 5.846 36 16.605.340 32 17.91 4.952 53 18.80 4.721 7 19.19 4.624 7 20.33 4.368 4 21.464.141 4 22.17 4.010 5 24.50 3.634 17 27.01 3.301 6 28.16 3.169 12 29.783.001 9 30.59 2.922 9 31.33 2.855 9 31.87 2.808 3 34.27 2.616 4 36.252.478 5

Crystalline form I-S of Saxagliptin Monohydrochloride obtained above hasan attenuated total reflectance IR spectrum with absorption bands at2907, 2853, 1637, 1589, 1462, 1391, 1318, 1045, 1014 and 775 cm⁻¹ (±2cm⁻¹; FIG. 2)

The obtained crystalline form I-S was subjected to differential thermalanalysis. As can be seen in FIG. 3 (lower curve), crystalline form I-Sshows no significant dehydration endotherm but only a peak at 241° C.(T_(onset) 230° C.; heating rate 10° C./minute, pinholed capsule).

Ionic chlorine was determined as 10.7% (theory 10.08%)

The water content of the obtained crystalline form I-S was determined as1.2% w/w using a Karl Fischer apparatus. At about 50% relative humidityat 25° C. form 1 S of Saxagliptin Hydrochloride shows a water content ofabout 1.5%. This water is lost completely when lowering the relativehumidity at 25° C. to about 0.5%. The process is reversible whenexposing Saxagliptin hydrochloride to a humidity of about 50%.

Form I-S is stable below 50% relative humidity. Above about 50% relativehumidity Form I-S transforms to the known Dihydrate H2-1. Thistransformation is not reversible.

Example 2 Preparation of Anhydrous Form I-S of SaxagliptinMonohydrochloride from Ethanol by Seeding

2.31 g Saxagliptin Monohydrochloride was suspended in 62 ml ethanol andthe resultant mixture was heated at reflux. The hot solution wasfiltered, then seeded with the product of example 1. The mixture wascooled to 25° C. and then put into a refrigerator over night. The whitesolid was collected by filtration and dried in a vacuum oven to give0.78 g of Saxagliptin Monohydrochloride form I-S.

Example 3 Preparation of Form HT-S of Saxagliptin Monohydrochloride

10 mg Saxagliptin Monohydrochloride Dihydrate was heated up to 180° C.with 10° K/min under Nitrogen. Form HT-S was obtained.

The powder X-ray diffraction pattern of Saxagliptin Monohydrochlorideform HT-S is shown in FIG. 4. Characteristic XRPD angles, d-spacings andrelative intensities are shown in Table 2.

TABLE 2 Angles 2-theta, d-values and relative intensities of form HT-SAngle d value rel. Int. [2-Theta °] [Angstrom] [%] 6.62 13.357 100 7.6311.591 3 10.11 8.749 7 11.48 7.707 7 12.08 7.326 3 13.27 6.673 14 15.285.799 40 16.69 5.313 18 17.60 5.039 35 19.15 4.635 8 19.97 4.446 1421.32 4.168 9 24.11 3.691 9

Crystalline form HT-S of Saxagliptin Monohydrochloride obtained abovehas an attenuated total reflectance IR spectrum with absorption bands at2906, 2854, 1649, 1574, 1513, 1459, 1338, 1124, 1032 and 851 cm⁻¹ (±2cm⁻¹; FIG. 5)

The obtained crystalline form HT-S was subjected to differential thermalanalysis. As can be seen in FIG. 3 (lower curve), crystalline form HT-Sshows no significant dehydration endotherm but only a peak at 230° C.(heating rate 10° C./minute, pinholed capsule).

The obtained crystalline form HT-S showed a water loss of not more than0.5% w/w based on thermogravimetric analysis (FIG. 6, upper line).

Example 4 Preparation of Form HT-IV-S Step 1, Preparation of Form IV-S

105 mg of Saxagliptin Monohydrochloride dihydrate form H2-1 weredissolved in 11 ml of n butanole. The solution obtained was filtered andthe solvent was removed by vacuo at approximately 20 mbar using arotavap. To the residue 4 ml of tert. amylalkohol were added and asuspension was obtained. The suspension was stirred for 3 days and thecrystals were than isolated by suction and kept in a dessicator at about30% relative humidity overnight.

Yield: 97 mg Saxagliptin Hydrochloride form IV-S

Step 2, Preparation of Form HT-IV-S

The crystalline product Saxagliptin Hydrochloride IV-S was dried in avacuum oven at 50° C. for approximately 10 hours at a vacuum of about40° C. followed by drying at about 80° C. for 5 hours to yieldcrystalline form HT-IV S

Water (KF): 0.7%

A sample was stored at 45-49% relative humidity for 12 hours.

Water (KF): 1.2%

No change in the crystal form was observed (FTIR).

The powder X-ray diffraction pattern of Saxagliptin Monohydrochlorideform HT-IV S is shown in FIG. 7. Characteristic XRPD angles, d-spacingsand relative intensities are shown in Table 3.

TABLE 3 angles 2-theta, d-values and relative intensities of formHT-IV-S Angle d value rel. Int. [2-Theta °] [Angstrom] [%] 2.56 34.561100 4.46 19.832 69 5.14 17.191 6 6.82 12.965 74 7.73 11.433 7 8.94 9.8896 13.69 6.47 15 13.93 6.357 6 14.64 6.05 70 15.1 5.866 23 15.77 5.618 2015.97 5.551 35 16.6 5.342 6 17.19 5.158 23 18.14 4.89 54 18.88 4.7 1720.27 4.381 9 26.99 3.304 6 27.67 3.223 5 28.11 3.175 7 28.47 3.135 729.53 3.026 13 31.92 2.804 7

Crystalline form HT-IV-S of Saxagliptin hydrochloride obtained above hasan attenuated total reflectance IR spectrum with absorption bands atwavenumbers of 3495, 2921, 1637, 1616, 1464, 1242, 1103, 1013, 940 and774 (±2 cm⁻¹; FIG. 8).

The obtained crystalline form HT-IV-S was subjected to differentialthermal analysis. As can be seen in FIG. 9, crystalline form HT-IV-sshows no significant dehydration endotherm but only a peak at 240° C.(T_(onset) 232° C. (heating rate 10° C./minuter, pinholed capsule).

Example 5 Preparation of Form IV-S of Saxagliptin Monohydrochloride

105 mg of Saxagliptin Monohydrochloride dihydrate form H2-1 weredissolved in 11 ml of n butanole. The solution obtained was filtered andthe solvent was removed by vacuo at approximately 20 mbar using arotavap. To the residue 4 ml of tert. amylalkohol were added and asuspension was obtained. The suspension was stirred for 3 days and thecrystals were than isolated by suction and kept in a dessicator at about30% relative humidity overnight.

Yield: 97 mg

The powder X-ray diffraction pattern of Saxagliptin Monohydrochlorideform IV-S is shown in FIG. 10. Characteristic XRPD angles, d-spacingsand relative intensities are shown in Table 4.

TABLE 4 Angles 2-theta, d-values and relative intensities of form IV-SAngle d value rel. Int. [2-Theta °] [Angstrom] [%] 2.35 37.566 14 4.0821.652 100 4.72 18.738 15 6.25 14.143 29 13.91 6.368 6 14.51 6.104 2314.89 5.948 5 15.64 5.667 39 16.69 5.312 22 18.55 4.784 29 19.37 4.58210 19.8 4.484 6

The obtained crystalline form IV-S was subjected to thermogravimetricanalysis. As can be seen in FIG. 11 crystalline form IV-S shows a massloss of about 12.8% starting up to 100° C. This mass loss corresponds to2.86 mol of water.

Moisture sorption analysis shows a water content of 13.1% at 40%relative humidity at 25° C. corresponding to 2.94 mol of water. Moisturesorption analysis shows a water content of 12.8% corresponding to 2.86%relative humidity at 0% relative humidity. The process is reversible.

At above 40% relative humidity form IV-S irreversible transforms toknown form Dihydrate H2-1.

1. Anhydrous crystalline forms of Saxagliptin hydrochloride having awater content of not more than 1.5% w/w.
 2. Saxagliptin hydrochlorideaccording to claim 1 of the formula


3. Crystalline Form I-S of Saxagliptin hydrochloride according to claim1 having a x-ray powder diffraction pattern comprising peaks at 6.7±0.2,14.6±0.2, 15.2±0.2, 16.6±0.2 and 17.9±0.2 degrees two-theta and/orhaving an infrared spectrum comprising peaks at wavenumbers of 2907,2853, 1637, 1589, 1462, 1391, 1318, 1045, 1014 and 775+/−2 cm⁻¹. 4.Crystalline Form HT-S of Saxagliptin hydrochloride according to claim 1having a x-ray powder diffraction pattern comprising peaks at 6.6±0.2,13.3±0.2 and 17.6±0.2 degrees two-theta and/or having an infraredspectrum comprising peaks at wavenumbers of 2906, 2854, 1649, 1574,1513, 1459, 1338, 1124, 1032 and 851+/−2 cm⁻¹.
 5. Crystalline FormHT-IV-S of Saxagliptin hydrochloride according to claim 1 having a x-raypowder diffraction pattern comprising peaks at 2.6, 4.5, 6.8, 14.6 and18.1±0.2 degrees two-theta and/or having an infrared spectrum comprisingpeaks at wavenumbers of 3495, 2921, 1637, 1616, 1464, 1242, 1103, 1013,940 and 774+/−2 cm⁻¹.
 6. Crystalline Form IV-S of Saxagliptinhydrochloride according to claim 1 having an x-ray powder diffractionpattern comprising peaks at 2.4, 4.1, 4.7, 6.3 and 15.6±0.2 degreestwo-theta.
 7. Pharmaceutical composition comprising an crystalline formof Saxagliptin according to claim 1 in an effective amount.
 8. A processfor the preparation of crystalline Saxagliptin hydrochloride Form I-Saccording to claim 3 comprising the step of allowing Saxagliptinhydrochloride to crystallize from an alcohol in the presence of seedcrystals of Saxagliptin hydrochloride Form I-S.
 9. A process for thepreparation of crystalline Saxagliptin hydrochloride Form HT-S accordingto claim 4 comprising the step of heating the known crystalline forms ofSaxagliptin hydrochloride form H2-1, H1.25-2 or H.75-3 to about 160° C.to 180° C., and isolating Form HT-S.
 10. A method of using crystallineSaxagliptin hydrochloride according to claim 1 alone or in combinationwith one or more types of antidiabetic agents and/or one or more othertypes of therapeutic agents which may be administered orally in the samedosage form for the preparation of a medicament in a separate dosageform or by injection.
 11. A pharmaceutical composition comprisingcrystalline Saxagliptin hydrochloride according to claim 1, wherein theequilibrium relative humidity of the composition is below 50%.
 12. Thepharmaceutical composition of claim 11, wherein the equilibrium relativehumidity of the composition is from 10% to 40%.
 13. A method of usingSaxagliptin hydrochloride form IV-S according to claim 6 for thepreparation of Saxagliptin hydrochloride form HT-IV-S according to claim5.
 14. The crystalline Form I-S of Saxagliptin hydrochloride accordingto claim 3 having a x-ray powder diffraction pattern comprising peaks at24.5±0.2 and 28.2±0.2 degrees two-theta.
 15. The crystalline Form HT-Sof Saxagliptin hydrochloride according to claim 4 having a x-ray powderdiffraction pattern comprising peaks at 11.5±0.2 and 16.7±0.2 degreestwo-theta.
 16. The crystalline Form HT-IV-S of Saxagliptin hydrochlorideaccording to claim 5 having a x-ray powder diffraction patterncomprising peaks at 2.6±0.2 and 6.8±0.2 two theta.
 17. Thepharmaceutical composition according to claim 7, formulated for use intreating diabetes and/or related diseases.